Photoaccumulation of Oxidised Electron Donors in the Isolated Photosystem II Reaction Centre Studied by Steady State Light-Induced Absorption Changes
The photosystem II reaction centre complex isolated in Triton X-100 (1,2) does not retain the intrinsic quinone acceptors, QA and QB, but does show electron transfer to the artificial electron acceptor, silicomolybdate (3). In the presence of this acceptor the light minus dark difference spectrum, which we attribute to oxidation of P680, includes a distinct shoulder at about 670 nm (4). Reaction centres isolated in Triton X-100 and investigated under aerobic conditions have been found to be very susceptible to photodamage (4,5). Here we have used maltoside-exchanged reaction centres and anaerobic conditions to investigate in more detail the photoaccumulation of oxidised chlorophyll donors and their absorption characteristics.
KeywordsReaction Centre PSII Reaction Centre Reaction Centre Complex Artificial Electron Acceptor Minus Oxygen
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